Rapid Diver Vs PSD BCD Test!

Transcription

1 Rapid Diver Vs PSD BCD Test Timed test results: Equipment to put on : Rapid Diver which includes, BCD and Full face mask, air turned on. Fins (Scubapro Jets with Spring Straps) Standard Weight belt. No exposure Protection to simulate using the Rapid Diver as a Rescue without wetsuit or Drysuit or other PPE (Hoods and Gloves). Rapid Diver as supplied 27ft3 LP Faber tank. First time for all users. Chris: 00:50 Frank: 00:45 Jesus: 00:43 Rapid Diver on, size adjusted, fins on and Full Face mask in place and cinched down. Equipment to put on: PSD BCD which includes primary 100ft3 tank, 19ft3 Pony bottle, BCD, Full Face mask, Optional integrated weight pockets (Not used during first test). Fins (Scubapro Jets with Spring Straps) Standard weight belt. No Exposure protection to simulate using the PSD BCD as a rescue without wetsuit or drysuit or other PPE (hoods and Gloves). PSD BCD as supplied 119ft3 Combined air supply. All divers highly familiar with BCD. Chris: 00:50 (Same time) Frank: 00:48 (+3 seconds from rapid diver) Jesus: 00:55 (+ 12 seconds from rapid diver) BCD on, Size adjusted, Fins on, Pony bottle around neck, Full face mask in place and cinched down.

2 ****For curiosity weight was transferred from standard weight belt to weight integrated pockets, Jesus (diver with the slowest time) was timed again, New time was 00:49, with a mistake in setting up which cost extra time to correct. ****Test diver Danny (2 hours prior experience with Rapid diver) time to deploy rapid diver was 00:31 seconds. But with no weight belt. Drysuit deployment timed Test: Purpose: Time how long it would take a diver to deploy a self donning drysuit with minimal underwear. Simulating using a drysuit for a rapid rescue during warmer weather, providing more protection than a work uniform or wetsuit. Chris: 00:30 Frank: 00:58 Jesus: 01:48 Second test after coaching: Chris: 00:32 Frank: 01:00 Jesus: 01:10 SAC Rates and Dive times with Rapid Diver vs. PSD BCD Purpose: to see how long a rapid diver system with the biggest tank (27ft3) would last in a moderate exercise situation. Divers were asked to swim normally around a pool. They were not instructed to swim fast or slow or to stress them selves out in any way. Their air was periodically check. Average Depth 7ft fresh water psi working pressure. SAC rates: Chris: 1600 PSI Start (Time Elapsed 5 minutes) 1100 PSI End: SAC 82.5 PSI/MIN. RMV =. 86ft3/Min (Tank would have lasted at that depth for 31 minutes to EMPTY) Frank: 2000 PSI start (Time Elapsed 10 minutes) 500 PSI end: SAC 123.8PSI min. RMV = 1.28ft3/Min (Tank would have lasted at that depth for 19 minutes to EMPTY) Jesus: 1100 PSI Start (Time Elapsed 4 minutes) 500 PSI end: SAC PSI/MIN. RMV = 1.29ft3/Min (Tank would have lasted at that depth for 21 minutes to EMPTY)

3 Assuming the same SAC and RMV rates on PSD BCD (100ft3 plus 19ft3 tanks) Divers air supply would have lasted: Chris: 138 minutes same depth and to EMPTY Frank: 92 Minutes same depth and to EMPTY Jesus: 93 Minutes same depth and to EMPTY Using SAC rates to determine how long the RAPID Diver system or PSD BCD will last at any given depth will significantly reduce all the numbers. Average depth was close enough to surface to not change the numbers much. Example at 2 ATA (33 ft Salt water) Frank s air supply on the rapid diver system would last 10 minutes to EMPTY. Depending on the regulator some may have issues delivering usable air when the tank pressure drops below 200 PSI, limiting the usable air in the system. Also breathing down a tank to 500 psi in any situation is not recommend due to the lack of reserves. ****Rapid Diver suggested SOG state that the Rapid Diver use should be limited to 20ft max. Using SAC rate to run the numbers, Frank the same diver from the example above air supply would last roughly 13 minutes to EMPTY without taking into consideration the regulators ability to deliver air regardless of tank pressure. *****Rapid Diver can be outfitted with an Aluminum 80 on it s back, but will just turn the system into an outdated horse collar BCD. All test were conducted as the Rapid diver system is meant to be dove, with a small pony style tank up front for immediate rescue**** ****Diver s air consumption rate is very subjective and depends on a tremendous amounts of variables. Divers can lower their SAC by relaxing and be becoming experienced. Anecdotal evidence suggest though during actual rescue scenarios where life and death is a very real consequence of the rescuer s actions, SAC/RMV rates of up to 3ft3/Min have been recorded and are not out of the ordinary. Weighting using Rapid Diver system vs PSD BCD Purpose: Rapid Diver creator claims that no weight is needed to dive Rapid Diver system. Without any exposure protection only 1 diver was able to use Rapid diver system without weight and that was only until the tank s pressure was above 1600 PSI. After that point the diver needed to add weight to the system in a fresh water pool without exposure protection. Most divers needed 5-8 lbs of weight to use the system in a fresh water pool. When using the PSD BCD no divers needed any weight until the tanks reached 1000psi where one diver needed to add 5 lbs of weight. Drysuit Use and the Rapid Diver system Drysuits where used well with the rapid diver system. A hose was NOT connected to inflate the Drysuit during the dive (An extra hose was not on the regulator but can easily be added)

4 The drysuits worked the same as if using a PSD BCD. The Rapid diver system horse collar shape though blocked the drysuit inflator. Working around this issue should be possible. All divers needed to add weight in order to use the drysuit with the Rapid diver. Minimal underwear was used (Fleece socks and bathing suit and rashguard). With the PSD BCD minimal amount of weight was needed for the same configuration. Diver s impression of the Rapid Diver system Most divers enjoyed swimming around and playing with the system. Saying that it allowed for more movement without the cumbersome tanks on their back, but in the same breath they also said the tank position was awkward at times and they touched bottom more often with the Rapid diver due to the tank positioning. Visibility of the chest was reduced with the Rapid diver system due to the shape of the BCD and Full Face mask. Finding tools was a harder with the Rapid diver system due to this lack of visibility. Most divers stated that when the RDS was inflated, it became much harder to swim around and Fought with the RDS. The RDS was in some opinions less stable than a standard BCD. Neutral buoyancy was easier to establish in a standard BCD vs the RDS but that may be due to the limited amount of time using the RDS system. Surface swimming was much easier on the back with the RDS, but standing still was harder due to tank positioning. Deflating the RDS was much harder than deflating a BCD due to air being trapped. Lack of pockets also lends itself to adding equipment where 1) it s hard to see 2) Lends itself to get caught up while making way through restrictions. Rapid Diver system Pros: Quicker (by mere seconds) to deploy Easy to adjust (even though most complained it wasn t as stable) One Size fits all (This is it s best quality, in the author s opinion) Less expensive when comparing a Standard PSD BCD with all components. Compact (easier to store than standard bcd) Rapid Diver neutral features ***May be a pro or con but is washed out for some other reason*** Lightweight (Adding needed weight belt to the system washed out the lightweight savings) Relatively customizable - The RDS can be used with an AL 80 but once it is turned into a regular BCD all pros except for Sizing disappear. Rapid Diver Cons Limited Air Supply Tank placement (below nipple line where most entanglements happen) limited redundancy options

5 When adding Al 80 tank position is awkward (one tank in the front and one in the back) Recommendations The Rapid Diver system is obviously a well thought out system, but I feel the benefits of the system are over-sold and are meant to fix a problem that for highly trained, highly experienced teams, may not exist. The RDS is a BCD with tank and Regulator attached. So is a BCD with tank and regulator attached. The RDS is just smaller. But with limited uses. Through our testing we found that for an extra 5-10 seconds of gearing up time the advantage of having 4 times the amount of available air for a diver would be worth the extra time. Also the redundancy afforded through use of a primary tank and secondary pony tank is indispensable when a dive goes wrong or equipment fails. An incredible amount of training and experience is needed to be able to make the risk vs reward judgment call to disregard using larger and redundant air supplies and should in no way shape or from be made by an inexperienced or untrained rescuer. To supply a would be rescuer with the equipment just because they are going to go in the water anyway is a dangerous and illadvised strategy. In my opinion seeking the right equipment and training and educating rescuers to stay out of the water without the proper equipment and training is money better spent. I cannot recommend the RDS for untrained or less trained dive teams that are not using Public Safety diver certification as their minimum qualifications. The RDS should not be used as a bandaid to get less trained rescuers into the water before the properly trained and experienced rescuers arrive on scene. A properly trained team should be able to deploy within 3 minutes, meaning from street clothes to fully dressed in PPE and at the water ready to affect a rescue. A rescue call with any amount of travel time wash away the benefits of the rapid diver. Some teams use the RDS as a first line tool with some success. Meaning they send in a RDS into the water first to make quick rescues while the rest of the team gets dressed. Allowing the first diver into water the extra time it takes to get dressed and have the same amount of safety features of a Standard BCD makes more sense to me than to send them in with less than optimal equipment. If this strategy is to be used, whom do you send it first? Most teams have the least experienced diver in the water first, the reasoning being they want a more experienced diver going in as a backup to rescue the first diver if need be. Also, less experience divers will never get the experience they need if they are always the last to go. So, do we send the least experience diver into the water first with the least amount of air or redundancy? Or, do we send the most experienced diver with the hopes that a lesser diver can make the rescue if something goes wrong? Exposure protection is also a concern when developing SOGs for the RDS. If wetsuits and Drysuits are to be used, why not take the extra 5 seconds to use a BCD for 4 times the amount of air? And if not using exposure protection, why not just use the BCD in the same capacity for 4 times the amount of air?

6 Where the RDS shines is in it s compactness. And limited use can be found for it in use in Helo operations or using off a jet ski or other confined staging area. Another use may be during Stand by where the diver may need to be in gear for long periods of time in a confined location where a fully dressed diver may be impractical. Or where there will not be a immediate need for a diver but a surface swimmer that may need to work with their head underwater. Somewhere in-between needing a snorkel and 100ft3 tank comes the RDS. The hard part is determining when that time is, before an incident. For a highly trained Public Safety dive team there may be limited use of the RDS. Using the RDS as your Dive teams only equipment is not in any way recommended by the author. The takeaway point is even a monkey with a garden hose may get lucky and make a good stop at a house fire but we can not bank on luck as rescuers. We must plan every dive/rescue as a worst case scenario and add as many safety features into all of our operations. Our team members and rescuers deserve to go home every time too. At this time I do not recommend that our team purchase or use the Rapid diver systems, but reserve the right to change my mind if situations change and the need for a system like the RDS becomes apparent.